Acidic Answers

Not all acids are the highly corrosive substances introduced to us by our chemistry teacher. Amino acids for example are the basis for life as we know it. While defining the origins and meanings of various elements in previous posts, the question of what is an acid and how it got its name came to mind. The answers are below and beginning with the word 'acid' itself.

Acid, rather unsurprisingly, got its name for its taste - remember acid drops? Derived from the Latin acidus or 'sour', this is ultimately from the Proto-Indo-European ak meaning 'sharp' but also used to mean 'pointed'. When it comes to the chemical names with which we are most familiar, these are self-explanatory. For example hydrochloric simply means 'composed of chloring and hydrogen'; Sulphuric is 'of or pertaining to sulphur'; Nitric derives its name from 'nitre'; boric from 'boron'; and carbonic is derived from 'carbon dioxide'.

Formic acid is familiar to anyone who has been on the receiving end of a nettle sting - that irritant is formic acid. It is also used by ants and German chemist Andreas Sigismund Marggraf first obtained a pure form by distilling it from red ants. The name comes from the Latin formica meaning 'ants'.

Acetic acid has been tasted by most of us, be it in pickle or splashed liberally on chips, it is commonly known as vinegar. The word comes to English from the French acetique meaning 'vinegar' and ultimately from the Latin vinum acetum or 'wine turned sour'. Incidentally 'vinegar is derived from the Latin vinum aigre with the same 'sour wine' meaning.

Oxalic is related to 'oxygen' for both first elements come from the Latin oxalis 'sharp' and ultimately from the Greek oxys 'sharp'.

Tartaric acid is found in foods such as apples, bananas, avocados, apricots and grapes and thus in wine. Its name is derived from tartar or bitartrate of potash, this from Greek tartaron, a reference to the 'tartar encrusting the sides of wine casks'. It is thought to be of Semitic origin but the exact source has yet to be identified.

Folic acid is a B vitamin, important during pregnancy, and derived from the Latin folium meaning 'leaf' as it is found in abundance in green leaves such as spinach.

Ascorbic acid is a naturally occurring antioxidant. Its name comes from Middle Latin scorbuticus or 'scurvy' as was originally a reference to Vitamin C which is an anti-scorbutic.

Citric acid is found in citrus fruits. Here 'citrus' is a Latin word referring to the citron tree, the name given to a tree with a lemon-like fruit and aromatic wood native to Africa and was the first citrus fruit available to the west.

Lactic acid is obtained from sour milk, the name meaning 'procured from milk' and ultimately derived from the Latin lac or 'milk'.

Uric acid is, as any gout sufferer will tell you, the acid in urine which crystallizes in the joint (usually of the big toe) to cause the pain. It is, of course, present in urine and also blood and came to English from the French orine. We can trace this back to a Proto-Indo-European we-r, used to mean 'water, liquid, milk' and the root of Sanskrit var 'water', Avestan var 'rain', Lithuanian jures and Old Norse ver both meaning 'sea', and Old Norse ur referring very specifically to 'drizzling rain'.